1.68+68×31+68×69+68×99 2.47×520+530×52,怎样简便计算?
问题描述:
1.68+68×31+68×69+68×99 2.47×520+530×52,怎样简便计算?
答
1.68+68×31+68×69+68×99
=1.68+68(31+69+99+1-1)
=1.68+68X200-68
=13533.68
2.47×520+530×52
=(2.47+53)52
=2884.44
答
68+68×31+68×69+68×99
=68+(31+69)×68+68×100-68
=68+6800+6800-68
=13600
47×520+530×52
=47×520+53×520
=520×(47+53)
=520×100
=52000
答
1.68+68×31+68×69+68×99
=68×(1+31+69+99)
=69×200
=13800
2.47×520+530×52
=470×52+530×52
=1000×52
=52000
答
1. 68(1+99+31+69)=68*200=13600
2.520(47+52+1)-520*1+52*(530-520)=520*100=52000